First paragraph:
When legislators are elected under the banner of one
political party and, between elections, decide to switch
parties, it raises interesting questions about
representative democracy and its core institutions. There
have been many studies of the correlates and consequences of
this behaviour in the United States, where, compared to many
other democracies, it is quite rare (Grose and Yoshinaka,
2003; McCarty et al., 2003; Nokken, 2000). Studies examining
party-switching in contexts outside the United States have
produced insights about why and when legislators switch
parties as well as what they gain by doing so. Even so, the
number of comparative studies on party-switching remains
small and analysis of party-switching remains an
insufficiently exploited opportunity in the study of
comparative party politics.

Figures and
Tables:

Table 1. Direction of Defections in the 161 Local
Legislators Included in the Dataset

Last Paragraph:
(first paragraph of conclusions) This study advances our
understanding of party-switching on several fronts. First,
the article provides insight into the logic of party
defection in South Africa, a case where patterns of
defection were broad. At first glance, most party-switching
in South Africa appears to be easily explained by a
narrative about an alliance break-up and a set of
politically opportunistic floor-crossing laws spearheaded by
the ANC. The evidence presented here shows that defection
activity was more complex than the aggregate data might
indicate. While a broader political narrative may account
for the emergence of party-switching, the nuances of the
pattern itself conformed very much to the logic of what
Desposato has called the 'highly structured, rational, and
constrained' market of 'parties for rent' (2006). All
legislators were influenced by factors such as the size of
the largest party, their position vis-a`-vis the largest
party and whether the law required them to make their moves
with co-defectors or allowed them to go it alone. The size
of the largest party in a legislature and,more broadly, the
relationship between the sizes of all major parties in a
legislature and the importance of certain size thresholds,
have emerged in several recent studies as explanatory
variables (Kato and Yamamoto, 2009; Laver and Benoit, 2003).
This study confirms these earlier results. In particular, it
provides suggestive evidence that it is, as Kato and
Yamamoto (2009) suggest, important to consider how the
environments within which legislators operate create
uncertainty about the future and how legislators may use
defection as a strategy for coping with this uncertainty. At
their core, parties in legislatures and those who seek
membership in themlive by the logic of thresholds even when
they speak in the language of ideas.